Image reading device and image forming device

Abstract

To satisfactorily convey a hard-to-bend document and satisfactorily read an image of the document.SOLUTION: An image reading device is provided with a curved conveyance path K1 that can convey a document D in a curved state in at least part thereof, and a first horizontal conveyance path K2 that can convey a document CD in a substantially horizontal state. The image reading device is further provided with a second horizontal conveyance path K3 that has the curved conveyance path K1 and the first horizontal conveyance path K2 connected in a branched manner on the upstream side in a conveyance direction or the downstream side in the conveyance direction, and can convey the document D or CD in the substantially horizontal state. The image reading device is provided with a first CIS 80 (image reading unit) that can read an image formed on an undersurface of the document D or CD passing through the second horizontal conveyance path K3. The image reading device can switch the conveyance path from the feeding to ejection of the document C or CD between one consisting of the curved conveyance path K1 and second horizontal conveyance path K3 and one consisting of the first horizontal conveyance path K2 and second horizontal conveyance path K3.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an image reading device that reads an image on a document, and an image forming apparatus that includes the image reading device, such as a copying machine, a printer, a facsimile machine, or a combination machine thereof or a printing machine. [Background technology]

[0002] Conventionally, in image forming devices such as copiers, printers, and printing machines, there have been known image reading devices that read images of documents, which are capable of switching between a document transport path when reading images of normal documents and a document transport path when reading images of hard documents that are difficult to bend, such as cash cards (see, for example, Patent Document 1).

[0003] In more detail, in the image reading device of Patent Document 1 and the like, when reading an image of a normal document, a conveying path including a curved conveying path is selected, and when reading an image of a hard document that is difficult to bend, a conveying path that extends in an approximately straight line in an oblique direction is selected. Summary of the Invention [Problem to be solved by the invention]

[0004] When reading an image of a hard document that is difficult to bend, conventional image reading devices select a transport path that extends diagonally in an approximately straight line so as not to pass through a curved transport path, which is expected to reduce problems such as damage to the document or problems with poor document transport. However, there is a possibility that the document may not be transported stably by passing it through a transport path that extends in an approximately straight line in a diagonal direction, or that the image of the document may not be read well by the image reading unit that is positioned diagonally along the transport path.

[0005] The present invention has been made to solve the above-mentioned problems, and aims to provide an image reading device and an image forming device that can smoothly transport documents that are difficult to bend and can smoothly read images on the documents. [Means for solving the problem]

[0006] The image reading device of the present invention includes a curved transport path that can transport a document in a curved state at least in a portion thereof, a first horizontal transport path that can transport the document in a substantially horizontal state, a second horizontal transport path that is branched and connected to the curved transport path and the first horizontal transport path on the upstream side or the downstream side of the transport direction, and that can transport the document in a substantially horizontal state, and an image reading unit that can read an image formed on the underside of a document passing through the second horizontal transport path. a document placement plate formed of a light-transmitting material on which a document can be placed in a substantially horizontal position; , an automatic document transport unit in which the curved transport path, the first horizontal transport path, and the second horizontal transport path are installed and which can open and close an area above the document placement plate; and an opposing plate which is made of a light-transmitting material and which can face a lower surface of a document passing through the second horizontal transport path; a conveying path from when the document is fed to when it is discharged can be switched between a path consisting of the curved conveying path and the second horizontal conveying path and a path consisting of the first horizontal conveying path and the second horizontal conveying path. When reading an image of a document transported by the automatic document transport unit, the image reading unit moves to a first position where it comes into contact with the lower surface of the opposing plate in a fixed state, and when reading an image of a document placed on the upper surface of the document placing plate, it moves to a second position where it comes into contact with the lower surface of the document placing plate, and when moving between the first position and the second position, it does not come into contact with either the opposing plate or the document placing plate. It is something. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an image reading device and an image forming device that can smoothly transport an original that is difficult to bend and can smoothly read an image on the original. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an overall configuration diagram showing an image forming apparatus according to a first embodiment of the present invention. [Figure 2] FIG. 1 is a diagram illustrating a configuration of an image reading device. [Figure 3] 1A is a diagram showing a state in which a normal document is conveyed in an image reading device, and FIG. 1B is a diagram showing a state in which a document that is difficult to bend is conveyed in an image reading device. [Figure 4] FIG. 2 is a diagram showing a state in which an original is placed on an original placement plate. [Figure 5] 5A is a diagram showing a moving mechanism of the image reading unit, and FIG. 5B is a diagram showing the image reading unit and the holder as viewed from the direction A in FIG. 5A. [Figure 6]These are side views of the automatic document transport unit, with (A) a view showing the automatic document transport unit in an open state with the pressure plate installed, and (B) a view showing the automatic document transport unit in an open state with the pressure plate removed. [Figure 7] FIG. 10 is a configuration diagram showing an image reading device as a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals, and redundant explanations will be appropriately simplified or omitted.

[0010] First, the overall configuration and operation of the image forming apparatus will be described with reference to FIGS. In Fig. 1, 1 denotes a copying machine as an image forming apparatus, and 10 denotes an image reading device that optically reads image information of an original D. Referring to Fig. 2, the image reading device 10 is composed of a scanner unit 2 in which a first CIS 80 as an image reading unit is installed, an automatic original transport unit M, and the like. Also, 3 indicates an exposure section (writing section) that irradiates exposure light L based on image information read by the image reading device 10 onto the photosensitive drum 5, 4 indicates an image creating section that forms a toner image (image) on the surface of the photosensitive drum 5, and 7 indicates a transfer section (image forming section) that transfers the toner image formed on the photosensitive drum 5 onto a sheet P (paper). Also, 12 and 13 indicate a feeding section in which sheets P such as paper are stored, 17 indicates a registration roller (timing roller) that transports the sheet P toward the transfer section 7, 20 indicates a fixing device that fixes the toner image (unfixed image) carried on the sheet P, 21 indicates a fixing roller installed in the fixing device 20, and 22 indicates a pressure roller installed in the fixing device 20. Also, 31 indicates a discharge tray on which the sheet P discharged from the image forming apparatus main body 1 is stacked.

[0011] With reference to FIG. 1, the operation of the image forming apparatus main body 1 during normal image formation will be described. First, in the image reading device 10, the original document D is transported (fed) from the first original document placement unit 60 and passes through the first CIS 80 (which is a contact image sensor). At this time, the first CIS 80 optically reads the image (image information) of the original document D passing through that position. The optical image information read by the first CIS 80 is converted into an electrical signal and then transmitted to the exposure unit 3 (writing unit). The exposure unit 3 then emits exposure light L, such as a laser beam, based on the image information in the electrical signal toward the surface of the photosensitive drum 5 of the imaging unit 4.

[0012] Meanwhile, in the image creating unit 4, the photosensitive drum 5 rotates clockwise in the figure, and after going through a predetermined image creating process (charging process, exposure process, and development process), an image (toner image) corresponding to the image information is formed on the photosensitive drum 5. Thereafter, the image formed on the surface of the photosensitive drum 5 is transferred onto a sheet P conveyed by a registration roller 17 in a transfer unit 7 serving as an image forming unit.

[0013] On the other hand, the sheet P conveyed to the transfer unit 7 (image forming unit) operates as follows. First, one of the multiple feeding units 12, 13 in the image forming apparatus 1 is automatically or manually selected (for example, the uppermost feeding unit 12 in the apparatus body 1 is selected). Then, the uppermost sheet of sheets P stored in the feeding unit 12 is fed by the feeding mechanism 52 (comprised of a feed roller, a pickup roller, a backup roller, etc.) and conveyed toward the conveying path. Thereafter, the sheet P passes through the conveying path on which multiple conveying rollers are arranged, and reaches the position of the registration rollers 17.

[0014] The sheet P that has reached the position of the registration roller 17 is conveyed toward a transfer unit 7 (image forming unit) in time for alignment with the image formed on the photosensitive drum 5. After the transfer process, the sheet P passes through the position of the transfer unit 7, and then reaches the fixing device 20 via a conveying path. The sheet P that has reached the fixing device 20 is fed between the fixing roller 21 and the pressure roller 22, where the toner image is fixed by the heat received from the fixing roller 21 and the pressure received from both members 21 and 22 (the fixing process). The sheet P after the fixing process with the toner image fixed is sent out from between the fixing roller 21 and the pressure roller 22 (the fixing nip), and then discharged from the image forming apparatus main body 1 and stacked on the discharge tray 31 as an output image. In this way, a series of image forming processes is completed.

[0015] Next, the image reading device 10 will be described in detail with reference to FIGS. As shown in Figure 2, the image reading device 10 is composed of a first document placing section 60 (first document table), a second document placing section 61 (second document table), a document discharge section 62 (paper output tray), a scanner section 2, a pickup roller 63, a separation roller 64, a feed roller 65, multiple pairs of transport rollers 66 to 72, a first CIS 80 and a second CIS 90 as image reading sections, a first contact glass 81 as an opposing plate, a second contact glass 82 as a document placing plate, a pressure plate 75, a moving mechanism 100 (see Figure 5), etc.

[0016] Here, the first document loading section 60 has an open space formed at the top, and is configured so that a user can load a document D (which is a normal document that can be bent) from above (it is configured so that a stack of multiple documents D can be loaded). Furthermore, the first document placement section 60 is configured so that a portion thereof can be raised and lowered so that the height position of the uppermost document D among the plurality of documents D stacked thereon is always constant. In addition, the image reading device 10 in this embodiment is provided with a second document placing section 61 that protrudes to the side of the device for placing a document CD that is difficult to bend (a hard document such as a credit card, plastic card, or extra-thick card), which will be described in detail later.

[0017] The document discharge section 62 is installed below the first document loading section 60, and is configured to discharge and load the document D (or hard document CD) after the image has been read by the first CIS 80 or the second CIS 90 (configured to discharge and load a stack of multiple documents).

[0018] Further, on the transport paths K1, K3 from the first document placing section 60 to the document discharge section 62, there are provided, in order from the upstream side, a pickup roller 63, an FRR type feeding mechanism (feed roller 65, separation roller 64), and multiple pairs of transport rollers 66 to 69, 72. These members 63 to 69, 72 function as transport means that transport the document D placed on the first document placing section 60 toward the first CIS 80 or the second CIS 90, and then transport the document D toward the document discharge section 62.

[0019] Referring also to Figure 3, the first CIS as an image reading unit is a contact image sensor that reads image information of the original D transported by the transport means and passing through the position of the first contact glass 81 (opposing plate) through the first contact glass 81. The first contact glass 81 serving as the opposing plate is made of a light-transmitting material such as glass, and is placed on the transport path.

[0020] Hereinafter, an operation of reading only an image formed on one side of the document D set on the first document placing section 60 (single-side reading operation) in the image reading device 10 configured as above will be described. First, documents D (with an image formed on the top surface) are loaded in the first document loading section 60 with their leading ends (leading ends in the transport direction) abutting against the reference wall. Then, when an instruction to read the image of the documents D (copy instruction) is given by operating an operation panel (not shown), the documents D are transported sequentially from the top on the first document loading section 60 by the pickup roller 63 toward the FRR type feeding mechanism (feed roller 65, separation roller 64). At this time, there is a possibility that multiple documents D will be transported, but due to separation by the FRR type, only the topmost document D is separated and sent to the downstream transport path. Thereafter, the document D transported to the transport path hits the nip portion of the pull-out roller 66, which has stopped rotating, and is subjected to skew correction (oblique feed correction). The skew-corrected document D is then transported downstream by the pull-out roller 66, which has started to rotate, and is transported to the position of the first CIS 80 (and the first contact glass 81) by the first and second transport roller pairs 67 and 68. The image (image information) of the document D is then optically read by the first CIS 80. Thereafter, the document D from which the image has been read is discharged to the document discharge section 62 by the pair of transport rollers 69 and the pair of discharge rollers 72. In this way, the document D set on the first document placing section 60 passes through a partially curved transport path and is transported in the direction of the arrow in FIG. 3(A). Such a series of document transport operations is repeated for all documents D stacked on the first document placement section 60.

[0021] When reading an image formed on the back side of the document D in addition to the image formed on the front side, the document D, whose image on the front side has been read by the first CIS 80 (and the first contact glass 81), is then transported to the position of the second CIS 90 (which is a contact image sensor).Then, the image on the back side of the document D is optically read by the second CIS 90. Thereafter, the document D, whose back side image has been read, is discharged to the document discharge section 62 by the pair of discharge rollers 72. The first and second CISs 80 and 90 extend in the width direction (the direction perpendicular to the paper surface of Figures 1 to 4) and are configured to include at least the entire width of the largest size document D (so that the image of the largest size document D can be read across the width).

[0022] Here, the image reading device 10 in this embodiment is configured to be able to transport a document (rigid document CD) that is difficult to bend (curve), in addition to a normal bendable document D, and read the image (image information) of the rigid document CD. More specifically, the second document placing section 61 for hard documents CD is installed so as to protrude to the side (the left side in FIGS. 1 to 4, etc.) of the image reading device 10 and extend substantially horizontally without being positioned below the automatic document transport section M (see FIG. 2). As shown in FIG. 3(B), the transport paths K2 and K3 from the second document placing section 61 to the discharge opening (an opening formed near the pair of discharge rollers 72 for discharging documents) are substantially linear transport paths so as not to bend (curve) the hard documents CD.

[0023] The rigid original CD placed on the second original placement section 61 is conveyed in a substantially straight line without being curved, as shown by the arrow in FIG. 3(B). Specifically, hard originals CD are set one by one in the second original placement unit 61 with their front surfaces (image reading surfaces) facing downwards so that their leading edges abut against the nip between the pair of feed rollers 70. When an instruction to read the image of the original D (copy instruction) is given by operating an operation panel (not shown), the hard original CD is fed by the pair of feed rollers 70 and then transported to the position of the first CIS 80 (and the first contact glass 81) by the pair of transport rollers 71. The image (image information) of the hard original CD is then optically read by the first CIS 80. The hard original CD from which the image has been read is then discharged to the original discharge unit 62 by the pair of transport rollers 69 and the pair of discharge rollers 72. At this time, when an image formed on the back surface of the hard original CD is to be read, the image on the back surface of the hard original CD is optically read by the second CIS 90 as the hard original CD passes the position of the second CIS 90. In this embodiment, the second document placing section 61 is configured so that rigid documents CD are set one by one, but it is also possible to configure so that a stack of rigid documents CD is set on the second document placing section 61. In that case, like the first document placing section 60, a part of the second document placing section 61 is configured to be able to move up and down, and an FRR type feeding mechanism is provided.

[0024] Here, the image reading device 10 in this embodiment does not read images while automatically transporting the document D (or hard document CD) (instead of transporting the document and reading the image using the automatic document transport unit M), but is configured to be able to read images even when the document D is fixed without being transported, as shown in Figure 4. More specifically, a second contact glass 82 is provided as a document placement plate on which a document D can be placed in a substantially horizontal state on the top surface of the scanner unit 2 (the surface facing the bottom surface of the automatic document transport unit M). The second contact glass 82 as a document placement plate is made of a light-transmitting material such as glass, and is configured so that the height of its top surface is substantially the same as the height of the top surface of the scanner unit 2. Also, referring to Figures 4, 6(A), etc., the automatic document transport unit M is configured so that the upper part of the second contact glass 82 (document placing plate) can be opened and closed, and a pressure plate 75 (which has appropriate elasticity, similar to known ones) is installed on the underside thereof.

[0025] As shown in Figure 4, when reading an image of an original D placed on the upper surface of the second contact glass 82 (original placement plate) (when the original D is fixed and image reading is performed), the original D is sandwiched between the second contact glass 82 and the pressure plate 75. Specifically, as shown in Fig. 6(A), the automatic document feeder M, which is in a closed state, is opened, and the document D (with the front side (image reading surface) facing downwards) is set on the upper surface of the exposed second contact glass 82. After that, the automatic document feeder M, which is in an open state, is closed so that the document D set on the second contact glass 82 is sandwiched between the pressure plate 75 (as shown in Fig. 4). Then, when an instruction to read the image of the original D (copy instruction) is given by operating an operation panel not shown, the first CIS 80 moves in the direction of the dashed arrow in Figure 4 (a direction perpendicular to the width direction, which is the scanning direction) while in contact with the underside of the second contact glass 82, and the image of the entire surface of the original D is optically read. As shown in Figure 4, in this embodiment, the first CIS80 (image reading unit) used when reading an image while the original D is fixed and not transported is movable and shared with the first CIS80 used when reading an image while the original D is transported by the automatic original transport unit M, and this will be described in detail later using Figure 5 etc.

[0026] The characteristic configuration and operation of the image reading device 10 (image forming device 1) according to this embodiment will be described in detail below with reference to FIGS. 2 to 6. 2 and 3, the image reading device 10 according to the present embodiment is provided with a curved transport path K1, a first horizontal transport path K2, and a second horizontal transport path K3.

[0027] The curved transport path K1 is a transport path that allows the document D to be transported in a curved state at least in a part thereof. Specifically, the curved transport path K1 in this embodiment is a transport path that extends from the position of the feed opening (FRR type feed mechanisms 64, 65) to a position upstream of the first CIS 80 (and the first contact glass 81), and is formed so that a portion of it (the transport path between the second transport roller pair 67 and the third transport roller pair 68) is curved, and the other portion extends almost straight (in a linear shape) with almost no curvature. This curved transport path K1 is used only when transporting a normal document D (a bendable document).

[0028] The first horizontal transport path K2 is a transport path that allows the document D to be transported in a substantially horizontal state. Specifically, the first horizontal transport path K2 in this embodiment is a transport path that extends from the position of the feed opening (the pair of feed rollers 70) to a position upstream of the first CIS 80 (and the first contact glass 81), and is formed so that the entire path extends straight and substantially horizontally. This first horizontal transport path K2 is mainly used when transporting hard documents CD (documents that are difficult to bend).

[0029] The second horizontal transport path K3 is a transport path that can transport the document D (including the rigid document CD) in a substantially horizontal state, and is connected to the curved transport path K1 and the first horizontal transport path K2 by branching off on the upstream side in the transport direction. Specifically, the second horizontal transport path K3 in this embodiment is a transport path that extends from a position upstream of the first CIS 80 (and the first contact glass 81) to the position of the discharge outlet (discharge roller pair 72), and is formed so that the entire path extends straight and approximately horizontally. The most upstream portion of the second horizontal transport path K3 is the point where the most downstream portion of the curved transport path K1 and the most downstream portion of the first horizontal transport path K2 join together. Therefore, this second horizontal transport path K3 is used both when transporting a normal document D and when transporting a rigid document CD.

[0030] Further, the second horizontal transport path K3 is provided with a first CIS 80 as an image reading unit capable of reading an image formed on the lower surface of a document D (including a hard document CD) passing through the second horizontal transport path K3. Furthermore, the second horizontal transport path K3 is also provided with a second CIS 90 that can read an image formed on the upper surface of a document D (including a hard document CD) passing through the second horizontal transport path K3. Further, the second horizontal transport path K3 is provided with a first contact glass 81 as an opposing plate that can face the lower surface of the document D (including a hard document CD) passing through the second horizontal transport path K3.

[0031] In this embodiment, the transport path from when the original D (CD) is fed to when it is discharged is configured to be switchable between one consisting of a curved transport path K1 and a second horizontal transport path K3, and one consisting of a first horizontal transport path K2 and a second horizontal transport path K3. Specifically, as shown in Figure 3(A), when a normal document D is transported (when the document D is fed from the first document loading section 60), the document D is discharged to the document discharge section 62 via the curved transport path K1 and the second horizontal transport path K3. 3(B), when a hard document CD is transported (when the document CD is fed from the second document placing section 61), the document CD passes through the first horizontal transport path K2 and the second horizontal transport path K3 and is discharged to the document discharge section 62. These transport paths K2 and K3 are substantially horizontal and in a substantially straight line from the paper feed opening to the discharge opening.

[0032] Here, in this embodiment, the portion where the curved conveying path K1 and the first horizontal conveying path K2 converge is open when viewed from the second horizontal conveying path K3 (downstream in the conveying direction). However, when the original D is transferred from the curved conveying path K1 to the second horizontal conveying path K3, and when the original CD is transferred from the first horizontal conveying path K2 to the second horizontal conveying path K3, inertia occurs due to the transport, so the original D is not erroneously transported from the curved conveying path K1 to the first horizontal conveying path K2, and the original CD is not erroneously transported from the first horizontal conveying path K2 to the curved conveying path K1. In addition, at the point where the curved conveying path K1 and the first horizontal conveying path K2 converge, a switching member can be installed that closes the most downstream portion of the first horizontal conveying path K2 when the original D is transferred from the curved conveying path K1 to the second horizontal conveying path K3, and closes the most downstream portion of the curved conveying path K1 when the original CD is transferred from the first conveying path K2 to the second horizontal conveying path K3.

[0033] In this way, the image reading device 10 in this embodiment is configured to be able to select the approximately horizontal conveying paths K2 and K3 instead of the conveying paths K1 and K3 including the curved conveying path K1 when transporting and reading images of a hard document (hard document CD) that is difficult to bend. Therefore, compared to when the hard original CD is transported in a straight line but at an angle (non-horizontal), the transportability of the original CD is stabilized, and the image of the hard original CD can be read well by the first CIS 80 (or the second CIS 90). Furthermore, since the second document placement section 61 is not disposed so as to protrude below the automatic document transport section M, the space below it can be used effectively (without interfering with the installation of post-processing devices such as a finisher). Furthermore, since the hard documents CD are discharged in a substantially horizontal direction toward the document discharge section 62, it is possible to effectively utilize the space below the discharge opening and set a large number of stacked documents in the document discharge section 62.

[0034] Here, in this embodiment, the first CIS 80 as an image reading unit is used both when reading images while transporting documents D and CD by the automatic document transport unit M as shown in Figures 3(A) and (B), and when reading images while document D is fixed without being transported as shown in Figure 4. This enables a reduction in cost of the image reading device 10. This effect is particularly noticeable when using an expensive first CIS 80 with high reading accuracy.

[0035] Specifically, when reading an image on a document D or CD being transported by automatic document transport unit M, first CIS 80 (image reading unit) moves to a first position (the position shown in FIGS. 2 and 3, and the position of first CIS 80 shown on the left side of FIG. 5(A)) where it is fixed to and in contact with the underside of first contact glass 81 (opposing plate). Then, first CIS 80 fixed to the first position reads an image on the entire surface of document D or CD that is moving relatively. In contrast, when reading an image of an original D placed on the upper surface of the second contact glass 82 (original placement plate), the first CIS 80 (image reading unit) moves to a second position (the position shown in FIG. 4, which is the position of the first CIS 80' shown on the right side of FIG. 5(A)) where it comes into contact with the lower surface of the second contact glass 82. Then, the first CIS 80 moves in a direction (scanning direction) perpendicular to the width direction at the second position, and reads an image of the entire surface of the fixed original D.

[0036] More specifically, the scanner section 2 of the image reading device 10 (a part that is fixed to the image forming device main body 1 and does not open or close in conjunction with the opening or closing of the automatic document transport section M) is provided with a moving mechanism 100 that moves the first CIS 80 between a first position and a second position. Furthermore, when reading an image of an original D placed on the upper surface of the second contact glass 82 (original placement plate), the first CIS 80 (image reading unit) reads the image while moving in a substantially horizontal direction (the direction of the dashed arrow in FIG. 4, which is the scanning direction) while in contact with the lower surface of the second contact glass 82. That is, the movement mechanism 100 is configured to be able to move the first CIS 80 between the first position and the second position, as well as to move the first CIS 80 in the scanning direction at the second position.

[0037] As shown in FIG. 5, the movement mechanism 100 is made up of a holder 110, a compression spring 111 (biasing member), a feed screw 116, a rod 117, a guide rail 115, a motor (not shown), and the like. The holder 110 holds the first CIS 80 so that it can move up and down, and has a compression spring 111 disposed therein that biases the first CIS 80 upward. The feed screw 116 and the rod 117 are arranged side by side at a distance in the width direction so as to extend in a direction perpendicular to the width direction. The feed screw 116 is threadedly engaged with a female thread portion 110a formed in the holder 110, and is configured to be rotatable in forward and reverse directions by a motor (not shown) controlled by a control unit. The rod 117 is fitted into a hole 110b formed in the holder 110. The guide rails 115 contact the upper surfaces of the protrusions 80a that protrude from both ends of the width of the first CIS 80, and are biased by the compression springs 111 to prevent the first CIS 80 from moving upward indefinitely.

[0038] With the moving mechanism 100 configured in this manner, the control unit controls the motor to move the first CIS 80 between the first position shown in Figure 3 and the second position shown in Figure 4 when switching the document reading operation, and moves the first CIS 80 in the scanning direction at the second position shown in Figure 4 when reading the document D on the second contact glass 82.

[0039] In this embodiment, the guide rail 115 is configured so that the first CIS 80 (image reading unit) does not come into contact with either the first contact glass 81 (opposing plate) or the second contact glass 82 (document placing plate) when moving between the first position shown in FIG. 3 and the second position shown in FIG. 4. This prevents the first CIS 80 from colliding with and damaging the first and second contact glasses 81, 82 when moving from the first position to the second position or from the second position to the first position.

[0040] In this embodiment, as shown in FIGS. 2 to 4, the first contact glass 81 (opposing plate) is disposed above the second contact glass 82 (original placing plate). That is, the first position where the first CIS 80 contacts the first contact glass 81 is located higher than the second position where the first CIS 80 contacts the second contact glass 82. Therefore, as shown in Fig. 5(A), the guide rail 115 is provided with a portion that extends substantially horizontally upward, a portion that extends substantially horizontally downward, and a portion that connects these portions (in this embodiment, the guide rail 115 is formed to extend diagonally in order to smooth the movement of the first CIS 80 between the first position and the second position and the up and down movement). In this way, by positioning the first contact glass 81 above the second contact glass 82, even when first and second horizontal transport paths K2 and K3 extending approximately horizontally are provided, sufficient space can be secured to provide a pressure plate 75 and a document discharge section 62 in the automatic document transport section M, which can be opened and closed above the second contact glass 82.

[0041] Here, in the image reading device 10 according to the present embodiment, the pressure plate 75 is detachably installed in the automatic document transport unit M, as shown in FIG. In other words, the pressure plate 75 is configured to be switchable between an operation of opening and closing the upper part of the second contact glass 82 in conjunction with the opening and closing operation of the automatic document transport unit M, and an operation of opening and closing the upper part of the second contact glass 82 without being linked to the opening and closing operation of the automatic document transport unit M. 6(B), when reading an image of a large document D' (such as a newspaper) that extends beyond the second contact glass 82, the image reading operation can be performed by the first CIS 80 while the automatic document feeder M is left open and the document D' on the second contact glass 82 is pressed down by the pressure plate 75 removed from the automatic document feeder M. Therefore, by closing the automatic document feeder M, problems such as bending of the portion of the document D' that extends beyond the second contact glass 82 are less likely to occur.

[0042] <Modification> As shown in FIG. 7, the image reading device 10 in the modified example also has a curved transport path K1, a first horizontal transport path K2, and a third horizontal transport path K3. In the image reading device 10 of the modified example, the second horizontal transport path K3 is connected to the curved transport path K1 and the first horizontal transport path K2, which branch off downstream in the transport direction. More specifically, the image reading device 10 (automatic document transport unit M) in the modified example is provided with one document placement unit 160 and two document discharge units 161 and 162. The first document discharge unit 161 is disposed above the document placement unit 160, and the second document discharge unit 162 is disposed to the side of the automatic document transport unit M. The second horizontal transport path K3 is a transport path that extends from the feed opening (downstream of the pickup roller 163, near the nip between the feed roller 165 and the separation roller 164) to a position downstream of the first CIS 80 (and the first contact glass 81), and is provided with a transport roller pair 166 and a transport roller 167. The curved transport path K1 is a transport path that extends from a position downstream of the first CIS 80 (and the first contact glass 81) to the discharge opening (where a discharge roller 170 is provided), and is provided with a plurality of transport roller pairs 168-170. The first horizontal transport path K2 is a transport path that extends from a position downstream of the first CIS 80 (and the first contact glass 81) to the discharge opening (where a discharge roller 172 is provided), and is provided with a transport roller pair 171.

[0043] In the modified example, the transport path from when the original D (CD) is fed to when it is discharged can be switched between a path consisting of a curved transport path K1 and a second horizontal transport path K3, and a path consisting of a first horizontal transport path K2 and a second horizontal transport path K3. Specifically, as shown in FIG. 7, when a normal document D is transported (when a normal document D is fed from the document loading section 160), the document D passes through the second horizontal transport path K3 and the curved transport path K1 and is discharged to the first document discharge section 161. On the other hand, when a hard original CD is transported (when a hard original CD is fed from the original placement section 160), the original CD passes through the second horizontal transport path K3 and the first horizontal transport path K2 and is discharged to the original discharge section 62. These transport paths K2 and K3 are substantially horizontal and in a substantially straight line from the paper feed opening to the discharge opening. Even when the image reading device 10 is configured in this manner, it is possible to smoothly transport the document CD, which is difficult to bend, and to smoothly read the image on the document CD. In addition, at the point where the curved conveying path K1 and the first horizontal conveying path K2 branch off, it is preferable to install a switching member that closes the most upstream portion of the first horizontal conveying path K2 when the original D is transferred from the second horizontal conveying path K3 to the curved conveying path K1, and that closes the most upstream portion of the curved conveying path K1 when the original CD is transferred from the second horizontal conveying path K3 to the first conveying path K2.

[0044] Also, referring to Figure 7, in the image reading device 10 of the modified example, the first CIS 80 as an image reading unit is used in common when reading images while transporting the originals D and CD by the automatic original transport unit M, and when reading images while the originals D are fixed and not transported. This allows the image reading device 10 to be manufactured at low cost.

[0045] As described above, the image reading device 10 of this embodiment is provided with a curved transport path K1 that can transport the document D in at least a portion thereof in a curved state, and a first horizontal transport path K2 that can transport the document CD in a substantially horizontal state. Furthermore, the curved transport path K1 and the first horizontal transport path K2 branch off and connect to each other on the upstream side or downstream side of the transport direction to provide a second horizontal transport path K3 that can transport the document D, CD in a substantially horizontal state. Also provided is a first CIS 80 (image reading unit) that can read images formed on the underside of the document D, CD passing through the second horizontal transport path K3. The transport path from when the document D, CD is fed to when it is discharged can be switched between a path consisting of the curved transport path K1 and the second horizontal transport path K3, and a path consisting of the first horizontal transport path K2 and the second horizontal transport path K3. This allows the document CD, which is less likely to bend, to be transported well, and the image on the document CD to be read well.

[0046] In this embodiment, the present invention is applied to an image reading device 10 installed in a monochrome image forming apparatus 1, but the present invention can naturally also be applied to an image reading device installed in a color image forming apparatus. Furthermore, in this embodiment, the present invention is applied to an image reading device 10 installed in an electrophotographic image forming apparatus 1, but the application of the present invention is not limited to this, and the present invention can also be applied to image reading devices installed in other types of image forming apparatuses (for example, inkjet type image forming apparatuses, stencil printing machines, etc.). In addition, in this embodiment, a curved conveying path K1 is used that can convey the original D in a curved state in part of it, but it is also possible to use a path that can convey the original Dwo in a curved state in its entirety. Even in such cases, the same effects as those of this embodiment can be obtained.

[0047] It is to be noted that the present invention is not limited to the present embodiment, and it is clear that the present embodiment can be appropriately modified within the scope of the technical concept of the present invention in addition to the modifications suggested in the present embodiment. Furthermore, the number, position, shape, etc. of the components are not limited to the present embodiment, and the number, position, shape, etc. of the components can be any number, position, shape, etc. that is suitable for implementing the present invention.

[0048] In this application, the term "original" is defined to include not only originals made of paper, but also hard originals such as credit cards, as well as all originals made of sheet-like materials such as transparencies. [Explanation of symbols]

[0049] 1. Image forming apparatus (image forming apparatus main body), 2 scanner unit, 10 Image reading device, 60 first document placement unit, 61 second document placement unit, 62 Original output section, 75 pressure plates, 80 1st CIS (image reading unit), 81 first contact glass (opposing plate), 82 second contact glass (document placement plate), 90 2nd CIS, 100 moving mechanism; D manuscript, CD hard copy, M Automatic document transport unit, K1 curved transport path, K2 First horizontal transport path, K3 Second horizontal transport path. [Prior art documents] [Patent documents]

[0050] [Patent Document 1] Patent No. 6540041

Claims

1. a curved transport path along which the document can be transported in a curved state at least in part; a first horizontal transport path along which the document can be transported in a substantially horizontal state; a second horizontal transport path that is branched off from the curved transport path and the first horizontal transport path and connected to the curved transport path on the upstream side or the downstream side in the transport direction, and that can transport the document in a substantially horizontal state; an image reading unit capable of reading an image formed on a lower surface of a document passing through the second horizontal transport path; an original placement plate formed of a light-transmitting material and capable of placing an original in a substantially horizontal state; an automatic document transport unit in which the curved transport path, the first horizontal transport path, and the second horizontal transport path are installed and which can open and close above the document placement plate; an opposing plate made of a light-transmitting material and capable of opposing a lower surface of the document passing through the second horizontal transport path; Equipped with a conveying path from when the document is fed to when it is discharged can be switched between a path consisting of the curved conveying path and the second horizontal conveying path and a path consisting of the first horizontal conveying path and the second horizontal conveying path, The image reading unit When an image of a document being transported by the automatic document transport unit is to be read, the counter plate is moved to a first position where the counter plate is fixedly in contact with the lower surface of the counter plate, When an image of a document placed on the upper surface of the document placement plate is to be read, the document placement plate is moved to a second position where the document placement plate is in contact with the lower surface of the document placement plate, An image reading device, characterized in that when moving between the first position and the second position, the image reading device does not come into contact with either the opposing plate or the document placement plate.

2. An image forming apparatus characterized by being equipped with the image reading device described in claim 1.

Images